The present invention pertains to a loader or apparatus for feeding signatures into a generally vertically extending pocket in which the signatures are supported on a folded edge and from which the signatures are fed by a feed mechanism, such as through a signature inserter to a saddle of a saddle gathering machine, as used in the manufacture of books, magazines, etc.
The present invention relates to a so-called "vertical hopper loader" since the signatures are fed into a generally vertically extending pocket. Feeding signatures into a generally vertically extending pocket in this manner is generally more difficult than feeding signatures by a "horizontal hopper loader", into a generally horizontally extending pocket or hopper, examples of which "horizontal hopper loader" are shown in prior art U.S. Pat. No. 3,674,258 granted on July 4, 1972 to Robert E. Maier, Jr. and James R. Moser on "Method and Apparatus for Feeding Stacked Sheet Material" (hereinafter called "'258 patent") and U.S. Pat. No. 3,904,191 granted Sept. 9, 1975 to Robert E. Maier, Jr. and Joseph P. McGinnis on "Hopper Loading Method and Apparatus" (hereinafter called "'191 patent"), respectively, having at its loading station signatures horizontally oriented and generally vertically oriented.
Some of the vertical loaders in the prior art include (1) U.S. Pat. No. 4,183,517 granted Jan. 15, 1980 to Carlton V. Hageman and James C. Wise on "Apparatus and Method for Delivering Signatures to a Gatherer". Hageman et al. disclose a mechanism for individually releasing signatures comprising pins controlled by solenoids actuated by photodetector relays; and (2) parent and divisional U.S. Pat. No. 4,177,982 granted Dec. 11, 1979 and U.S. Pat. No. 4,180,259 granted Dec. 25, 1979 to Elmer Bewersdorf et al. on respectively "Sheet Feeders" and "Varying the Drop of Sheets into a Hopper", hereinafter collectively called the "Bewersdorf et al. patents".
Bewersdorf et al. disclose a feeder which comprises a supply station in which signatures are stacked on their folded edge, and feeding means for delivering signatures into a vertical hopper. An upright stop plate is provided for supporting the signatures at the supply station. The feeding means includes a pair of feed belts for delivering signatures to the vertical hopper, and a suction manifold and stripper belts for individually extractting signatures from a stack of signatures leaning against the stop plate.
Difficulties in operating vertical loaders such as disclosed in Bewersdorf et al. patents consist in that a large quantity of signatures cannot be loaded in the loader without interfering with the predetermined feeding of signature at the supply station, and that the loaders cannot handle very short and very long signatures without substantial changes in the feeding mechanism. Further, the loaders are characterized by a constant riffling, sliding and jostling action that results in damage to the folds on the signatures when they move between conveyor belts.